Anchor trolley and fall arrest system and method implementing the same

ABSTRACT

A fall arrest anchor trolley for arresting the fall of a user. In one embodiment, the invention can be a system for arresting movement of a worker after falling from an elevated work surface comprising: a rail; a trolley in rollable contact with the rail, the trolley having a body, a brake sub-system, and a plurality of wheels, the brake sub-system comprising a brake rod, a brake pad connected to the brake rod, a lanyard connector connected to the brake rod, and a resilient element; the brake rod slidably coupled to the body so that the brake sub-system is alterable between: (1) a free state in which the brake pad is spaced a distance above the rail; and (2) an arrest state in which at least a portion of the brake pad frictionally engages the rail; the resilient element biasing the brake sub-system into the free state.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/639,284, filed Mar. 5, 2015, which is a continuation of U.S.patent application Ser. No. 13/686,713, filed Nov. 27, 2012, now U.S.Pat. No. 8,978,821, which: (1) claims the benefit of U.S. ProvisionalApplication Ser. No. 61/580,940, filed Dec. 28, 2011; and (2) is acontinuation-in-part of U.S. patent application Ser. No. 12/500,897,filed Jul. 10, 2009, now U.S. Pat. No. 8,316,990, the entireties ofwhich are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to a fall protection apparatus,system, and or method, and more specifically to a fall protection systemthat arrests longitudinal movement of a trolley along a rail upon a userfalling from a work surface and a method of arresting movement of aworker after falling off an edge of a work surface.

BACKGROUND OF THE INVENTION

Many work situations require workers to be positioned on top ofplatforms or vehicles that cannot be practically protected by aguardrail system enclosing the work surface. To prevent the workers fromfalling from such elevated positions and thereby sustaining serious orfatal injuries, various fall protection systems can be used. In general,fall arrest or fall protection systems are designed to prevent theworker from reaching an unprotected edge or to quickly stop a fallbefore the worker impacts a lower level. Such systems typically includea trolley secured to a structure overhead the work surface, a safetyharness worn by the worker, and a lanyard interconnecting the trolley tothe harness.

In using conventional fall arrest or fall protection systems, workerswho fall from the work surface are carried by momentum a distance fromthe work surface. As a result, workers are left hanging from the trolleyand lanyard until a third party or rescue team arrives at the scene toassist the worker. This can be extremely undesirable because if a workeris left hanging for an extended period of time, the worker may sufferfrom orthostatic intolerance or suspension trauma.

Thus, a need exists for a fall arrest apparatus, system and/or methodthat prevents a worker who falls from a work surface from sufferingorthostatic intolerance and negates the need for third party assistanceto rescue the worker.

BRIEF SUMMARY OF THE INVENTION

These and other needs are met by the present invention, which isdirected to a fall arrest apparatus, system and method. In one aspect,the invention can be a fall arrest system comprising: a rail extendingalong a longitudinal axis, the rail comprising a floor and alongitudinal slot separating the floor into a first longitudinal sectionand a second longitudinal section; a trolley comprising a body, a brakesub-system, and a plurality of wheels rotatably coupled to the body, theplurality of wheels in rolling contact with upper surfaces of the firstand second longitudinal sections; the brake sub-system comprising abrake rod, a brake pad connected to the brake rod, a lanyard connectorconnected to the brake rod, and a resilient element, the brake padpositioned above the first and second longitudinal sections; the brakerod slidably coupled to the body so that the brake sub-system isalterable between: (1) an arrest state in which the brake padfrictionally engages the upper surfaces of the of the first and secondlongitudinal sections of the rail to prohibit rolling movement of thetrolley along the rail; and (2) a free state in which the brake pad isspaced a distance above the upper surfaces of the first and secondlongitudinal sections of the rail to allow rolling movement of thetrolley along the rail; and the resilient element biasing the brakesub-system into the free state.

In another aspect, the invention can be a fall arrest trolleycomprising: a body, a brake sub-system, and a plurality of wheelsrotatably coupled to the body, wherein bottoms of the plurality ofwheels collectively define a rolling plane; the brake sub-systemcomprising a brake rod, a brake pad connected to the brake rod, alanyard connector connected to the brake rod, and a resilient element;the brake rod slidably coupled to the body so that the brake sub-systemis alterable between: (1) a free state in which the brake pad is spaceda distance above the rolling plane; and (2) an arrest state in which atleast a portion of the brake pad is located within the rolling plane;the resilient element biasing the brake sub-system into the free state.

In yet another aspect, the invention can be a method of arresting a userfrom falling off an edge of a work surface comprising: a) coupling afirst end of a lanyard to a lanyard connector of a fall arrest trolley,the fall arrest trolley comprising a plurality of wheels in rollingcontact with an upper surface of a rail extending along a longitudinalaxis; b) upon a user moving on the work surface, the fall arrest trolleyrolling along the upper surface of the rail, the trolley comprising abrake sub-system comprising, a brake rod, a brake pad connected to thebrake rod and located above the upper surface of the rail, the lanyardconnector connected to the brake rod, and a resilient element, whereinthe resilient element biases the brake sub-system into a free state inwhich the brake pad is spaced a distance above the upper surface of therail to allow the rolling of the trolley along the rail while the usermoves on the work surface; and c) upon the user moving off the edge ofthe work surface, the user's weight exerting a downward vertical forceon the lanyard connector that overcomes a spring force of the resilientmember and alters the brake sub-system into an arrest state in which thebrake pad frictionally engages the upper surface of the rail to prohibitfurther rolling of the trolley along the rail.

In a still further aspect, the invention can be a trolley for movementalong an elevated track to support a person who has fallen off of astructure adjacent the track, said trolley comprising a frame having atleast one roller, a connector mounted on the frame, and a trolleyimmobilizing assembly mounted on the frame, said at least one rollerenabling said trolley to roll along a surface of the track in alongitudinal direction, said connector having a lanyard releasablysecured thereto, the lanyard connected to a safety harness to be worn bythe person and to suspend the person from said trolley, said trolleyimmobilizing assembly comprising a movable engagement member and aflexible strap, said movable engagement member being biased in aposition away from the track, wherein pulling on said strap causes themovable engagement member to be pulled into engagement with the trackthereby releasably fixing said trolley at a fixed longitudinal positionon the track so that the person can swing below said trolley while fixedin the fixed longitudinal position on the track, and wherein releasingsaid strap causes the movable engagement member to return to the biasedposition thereby releasing the trolley from the fixed longitudinalposition on the track so that momentum of the swing of the person movessaid trolley along the track to another longitudinal position thereon.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is an isometric view showing one exemplary embodiment of a fallarrest self rescuing trolley constructed in accordance with thisinvention;

FIG. 2 is a side elevation view partially broken away of the trolleyshown in FIG. 1 mounted on an enclosed track;

FIG. 2A is an enlarged sectional view taken along line 2A-2A of FIG. 2;

FIG. 2B is an enlarged side elevation view of the portion of the trolleyshown within the circle 2B in FIG. 2;

FIG. 3 is a top plan view, partially broken away, of the trolley shownin FIG. 1;

FIG. 4 is an enlarged side elevation view of the portion of the trolleyshown within the circle 4 in FIG. 2;

FIG. 5 is an enlarged side elevation view of the portion of the trolleyshown within the circle 5 in FIG. 2;

FIG. 6 is an isometric view showing another exemplary fall arrest selfrescuing trolley constructed in accordance with this invention, i.e., atrolley for use on an I-beam;

FIG. 7 is a side elevation view partially broken away, of the trolleyshown in FIG. 6 mounted on an I-beam;

FIG. 7A is an enlarged sectional view taken along line 7A-7A of FIG. 7;

FIG. 8 is a top plan view, partially broken away, of the trolley shownin FIG. 7;

FIG. 9 is an enlarged side elevation view of the portion of the trolleyshown within the circle 9 in FIG. 7;

FIG. 10 is an enlarged side elevation view of the portion of the trolleyshown within the circle 10 in FIG. 7; and

FIG. 11-14 are a series of illustrations showing an exemplary use of afall arrest, safety system including a trolley constructed in accordancewith this invention.

FIG. 15 is a perspective view of a fall arrest anchor trolley inaccordance with another embodiment of the present invention;

FIG. 16 is an exploded view of the fall arrest anchor trolley of FIG.15;

FIG. 17 is a side view of the fall arrest anchor trolley of FIG. 15;

FIG. 18 is side view of the fall arrest anchor trolley of FIG. 15disposed within a rail;

FIG. 19 is a cross-sectional view taken along line IXX-IXX of FIG. 18;

FIG. 20 is a cross-sectional view taken along line XX-XX of FIG. 18;

FIG. 21 is a cross-sectional view taken along line XXI-XXI of FIG. 18with a brake sub-system in a free state;

FIG. 22 is a cross-sectional view taken along line XXII-XXII of FIG. 19with the brake sub-system in the free state;

FIG. 23 is the cross-sectional view of FIG. 19 with the brake sub-systemin an arrest state;

FIG. 24 is the cross-sectional view of FIG. 18 with the brake sub-systemin the arrest state;

FIG. 25 is the fall arrest anchor trolley disposed within the rail ofFIG. 18 with a user standing on a work surface and attached to the fallarrest anchor trolley by a lanyard;

FIG. 26 is a perspective view of a fall arrest anchor trolley inaccordance with yet another embodiment of the present invention;

FIG. 27 is a side view of the fall arrest anchor trolley of FIG. 26;

FIG. 28 is a front view of the fall arrest anchor trolley of FIG. 26;

FIG. 29 is a cross-sectional view taken along line XXIX-XXIX of FIG. 27;

FIG. 30 is a close-up view of area XXX of FIG. 27; and

FIG. 31 is a perspective view of the brake pad of the fall arrest anchortrolley of FIG. 26 removed therefrom.

DETAILED DESCRIPTION OF THE INVENTION

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

The description of illustrative embodiments according to principles ofthe present invention is intended to be read in connection with theaccompanying drawings, which are to be considered part of the entirewritten description. In the description of embodiments of the inventiondisclosed herein, any reference to direction or orientation is merelyintended for convenience of description and is not intended in any wayto limit the scope of the present invention. Relative terms such as“lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,”“down,” “top” and “bottom” as well as derivatives thereof (e.g.,“horizontally,” “downwardly,” “upwardly,” etc.) should be construed torefer to the orientation as then described or as shown in the drawingunder discussion. These relative terms are for convenience ofdescription only and do not require that the apparatus be constructed oroperated in a particular orientation unless explicitly indicated assuch. Terms such as “attached,” “affixed,” “connected,” “coupled,”“interconnected,” and similar refer to a relationship wherein structuresare secured or attached to one another either directly or indirectlythrough intervening structures, as well as both movable or rigidattachments or relationships, unless expressly described otherwise.Moreover, the features and benefits of the invention are illustrated byreference to the exemplified embodiments. Accordingly, the inventionexpressly should not be limited to such exemplary embodimentsillustrating some possible non-limiting combination of features that mayexist alone or in other combinations of features; the scope of theinvention being defined by the claims appended hereto.

Two structural embodiments of fall arrest systems are disclosed hereinthat are directed to eliminating a situation where a worker becomesstranded while hanging from a trolley and/or rail system after fallingfrom a work surface. Specifically, the first structural embodiment is afall arrest self-rescue trolley system and the second structuralembodiment is a fall arrest anchor trolley system. Each of thesestructural embodiments will be discussed in detail below, wherein FIGS.1-14 and the accompanying description disclose the fall arrestself-rescue trolley system and FIGS. 15-25 and the accompanyingdescription disclose the fall arrest anchor trolley system.

Fall Arrest Self Rescue Trolley

Referring to FIGS. 1-14, a fall arrest self rescue trolley 20 will bedescribed in accordance with an embodiment of the invention. Thedescription of the fall arrest self rescue trolley 20 and the systemwithin which that trolley operates will be made with reference to FIGS.1-14.

Referring first to FIG. 1, one exemplary embodiment of a fall arrestself rescue trolley 20 of a fall arrest safety system constructed inaccordance with this invention is illustrated. The trolley 20 isarranged for mounting and movement along an elevated track 10 (FIGS. 2and 2A) located adjacent the structure e.g., rail car 14 (FIGS. 11-14)on which a worker 12 is working and serves to support the worker in casehe/she falls off of the structure to prevent the worker from beinginjured in the fall. To that end, a conventional retractable lanyard 16(FIGS. 11-14) and a conventional safety harness (not shown) worn by theworker is connected to the trolley 20. The lanyard, harness and elevatedtrack form a portion of the fall arrest safety system. Unlike prior arttrolleys, each trolley of this invention is constructed so that theworker can operate the trolley to move himself/herself from the positionat which he/she is suspended after a fall to some other position, e.g.,a safety position from which the worker can descend, all withoutrequiring the help or assistance of anyone else.

As best seen in FIGS. 1 and 2 the trolley 20 basically comprises anelongated frame 22 formed of any suitable strong material, e.g., steel,aluminum, etc. The frame 22 includes a central section on which twopairs of rollers 24A and 24B are mounted via respective axles 26.Another pair of similarly constructed rollers 24C is mounted at one endof the frame and still another pair of similarly constructed rollers 24Dis mounted at the opposite end of the frame. Each of the rollers of eachpair is formed of a tough, wear resistant material, such as polyamide,but can be formed of any other material used in conventional enclosedtrack trolleys.

Each of the rollers of each pair is arranged to roll on a respectiveflange portion of the elevated track 10. In particular, as best seen inFIG. 2A, the track 10 is of a conventional “enclosed-type” construction.One particularly suitable enclosed track is that sold by SPANCO, adivision of Transol Corporation, the assignee of this invention. Thetrack 10 is an elongated member that is formed of a strong material,e.g., steel, and has a horizontally disposed top wall 10A, a pair ofvertical sidewalls 10B and 10C projecting downward from the top wall, apair of angularly located sidewalls 10D and 10E located below thevertical sidewalls, respectively, and a pair of horizontally disposedflanges 10F and 10G projecting inward from the ends of the angularlylocated sidewalls, respectively, to form a slot therebetween. The track10 is arranged to support the trolley 20 to enable the trolley to bemoved along the track to any desired longitudinal position by the user(as will be described later). In particular, the rollers of the pair 24Dare arranged to roll along respective flanges 10F and 10G of the track10. In a similar manner the rollers of the pair 24C are arranged to rollalong respective flanges 10F and 10G of the track 10, while the rollersof the pair 24A and the rollers of the pair 24B also roll alongrespective flanges 10F and 10G of the track. Thus, the trolley 20 can bemoved (rolled) to any longitudinal position along the length of thetrack 10.

A swivel eyelet 28 is mounted on the frame 22 immediately below thecentral roller pairs 24A and 24B. The eyelet 28 serves as the connectionpoint to which a conventional retractable lanyard 16 and its associatedsafety harness (not shown) may be secured, as best seen in FIGS. 1 and2. Thus, when a worker 12 is wearing a safety harness that is connectedvia a retractable lanyard 16 to the eyelet 28, he/she will be protectedfrom injury in the event of a fall. In such an event the retractablelanyard will act in its normal manner to arrest the fall, whereupon theworker will be suspended from the trolley 20 at the particularlongitudinal position on the track that the trolley is located when theworker's fall is arrested.

As mentioned earlier, the trolley 20 of this invention is arranged to beoperated by a worker suspended from it to move it along the track to aposition of safety. To that end, the trolley 20 includes at least onetrolley immobilizing assembly which is arranged when actuated to fix orimmobilize the trolley on the track and to hold the trolley in thatposition until its release is desired. In the exemplary embodimentsshown herein each trolley includes two trolley immobilizing assemblies28A and 28B. Each of these exemplary assemblies serves to releasablyengage the track when operated to releasably fix the trolley in positionon the track to enable the suspended worker to pull himself/herselfalong the track. In particular, one track engaging assembly 28A ismounted on the frame 22 at one end thereof to enable a suspended workerto move in the direction toward that end of the trolley, while the otherand identically constructed track engaging assembly 28B is mounted onthe opposite end of the frame 22 to enable a suspended worker to move inthe direction toward the opposite end of the trolley.

The track engaging assemblies 28A and 28B are identical in constructionand operation and each assembly basically comprises a movable frictionalengagement member 30, a flexible strap 32 and a retractor 34. Themovable frictional engagement member 30 is in the form of a locking barwhich is pivotally mounted adjacent a respective end of the frame 22 viaa respective pivot pin, e.g., a bolt 36. Each locking bar 30 includes anarcuate working end 38 (FIG. 5) which is arranged to be pivoted intofrictional engagement with a portion of the inside surface of the topwall 10A of the track 10. The opposite end of each locking bar 30 is inthe form of an angularly extending arm 40. A respective tension spring42 (FIG. 4) is provided to normally bias its associated locking bar sothat the working end 38 of that locking bar is spaced from and not infrictional engagement with the top wall 10A of the track 10. As bestseen in FIG. 4, each biasing spring 42 is mounted between the associatedfree end of the frame 22 and the point on the associated locking barfrom which the arm 40 extends.

Each locking bar 30 is arranged to be pivoted by the user (i.e., asuspended worker) by means of the strap 32 into its operativeorientation wherein its free end frictionally engages the top wall ofthe track. To that end, one strap 32 extends from a point at which it isaffixed to the retractable lanyard 16 to the retractor 34 at one end ofthe frame 22. The other strap extends from a point at which it isaffixed to the retractable lanyard 16 to the retractor 34 at theopposite end of the frame 22. Each retractor is mounted adjacent thefree end of the arm 40 of the associated locking bar and basicallycomprises an internal reel on which a portion of the associated strap 32is wound. The reel is internally biased so as to naturally wind up thestrap on it.

In order to keep each strap out of the way of the worker (to stow thestrap) until it is necessary to use it, the trolley 20 includes a pairof releasable guide assemblies 44 (FIG. 2B), each of which includes apin 44A over which a portion of the associated strap 32 extends. Inparticular, one guide assembly 44 is mounted on the frame 22 below andslightly beyond the center roller pair 24A and the other guide assemblyis mounted on the frame below and slightly beyond the center roller pair24B. Thus, each of the straps 32 extends generally horizontally close tothe track 10 from its associated retractor over the pin 44A of theassociated guide assembly 44 and from that point downward generallyvertically close to the retractable lanyard 16 to its connection point(not shown) on the lanyard. Each guide assembly 44 is releasably securedto the frame 22 by a respective pivotable finger 46 which is biased by aspring 46A.

Referring now to FIGS. 6-10, the details of an alternative embodiment ofa trolley 20′ constructed in accordance with this invention will now bedescribed. The trolley 20′ is arranged for use on an I-beam type oftrack 10′, like shown in FIG. 7A, and is of the same basic constructionas the trolley 20, except for the rollers and their mountings. In theinterest of brevity the common components of the trolleys 20 and 20′will be given the same reference numbers and a description of theirconstruction and operation will not be reiterated. Thus as can be seenin FIGS. 6 and 7, the frame 22 of the trolley 20′ includes a centralsection on which two pairs of rollers 24A′ and 24B′ are mounted viarespective axles mounting plates 50 and associated axle bolts 52. Theplates are held together by a pair of threaded rods 50A. Another pair ofsimilarly constructed rollers 24C′ is mounted at one end of the framevia respective mounting plates 54 and axle bolts 52. The plates 54 areheld together by a threaded rod 54A. Still another pair of similarlyconstructed rollers 24D′ is mounted in a similar manner at the oppositeend of the frame 22. Each of the rollers of each pair is formed of atough, wear resistant material, such as polyamide, but can be formed ofany other material used in conventional enclosed track trolleys. Each ofthe rollers of each pair is contoured and arranged to roll on the edgeof a respective lower flange portion of the I-beam that forms theelevated track 10′ as shown clearly in FIG. 7A.

Operation of a trolley constructed in accordance with this inventionwill now be described with reference to the illustrations in FIGS.11-14. In particular, those figures show the use of a system to protecta worker 12 from falling off of a railroad car 14. The worker 12 iswearing a conventional harness (not shown) that is connected by aconventional self-retractable lanyard 16 to the trolley 20/20′. Thetrolley in this example is shown mounted on an elevated track 10/10′.The track can be of the enclosed track type like shown in FIGS. 1-5 orcan be of the I-beam type like shown in FIGS. 6-10, or on other types ofbeams, such as H-beams, W-beams (for “wide flange”), rolled steel joist(RSJ), or double-T, or can be used on an on any other elongated supportmember having a flange or surface along which the roller(s) of a trolleyconstructed in accordance with this invention can roll.

In the exemplary use of the trolley 20/20′ shown in FIGS. 11-14, itshall be assumed that the worker 12 is working on the top of the railcar 14, as shown in FIG. 11, and has moved too close to the edge of therail car so that he/she slips and loses his/her balance and falls off ofthe rail car. The person is prevented from falling to the ground, i.e.,his/her fall is arrested, by the safety harness and lanyard that areconnected to the trolley 20/20′. It is likely that the momentum of theperson falling off of the back of the rail car will push the person awayfrom the rail car (and hence from safety) as shown by the arrows in FIG.12. If the trolley suspending the person is of a conventional type, theperson would be stuck in that position out of reach of the rail car sothat there would be nothing for him to grab onto to push or pull on tosafety. In contradistinction, the fall arrest self rescue trolleys ofthis invention enable the suspended worker to readily movehimself/herself along the track 10/10′ back to some safe location, e.g.,the rail car or some other structure adjacent to the track. To that end,once the person's fall has been arrested, the person merely has to reachup to activate a respective one of the track engaging assemblies asshown in FIG. 13. In particular, the person pulls on the strap 32 thatis facing in the direction that he/she wishes to move, e.g., in thedirection of the horizontal arrow shown in FIG. 13. Pulling on thatstrap causes it to unreel from its associated retractor 34. When thestrap has been fully unreeled from the retractor, further pulling on thestrap applies a downward force on the spring biased retaining finger 46(FIG. 2B). This action overcomes the bias on the finger, whereupon itpivots downward to release the guide assembly 44, whereupon the guideassembly falls away. Further pulling on the strap 32 by the personcauses it to pivot the associated locking bar 30 about the bolt 36,whereupon the working end 36 of the locking bar moves into frictionalengagement with the top wall 10A/bottom flange 10A′ of the track. Thisaction effectively locks the trolley in place giving the person ananchor point to which he/she can pull himself/herself. In particular,the person merely has to pull on the strap and swing himself/herselfforward toward the anchored end of the trolley, e.g., toward the railcar as shown by the arrows in FIG. 13. Once the swing begins the personcan release the strap 32, whereupon the bias of the spring 42 causes thelocking bar 30 to pivot back, i.e., disengage, from the track 10/10′ sothat the momentum of the swing of the person moves the trolley 20 alongthe track to a longitudinal position closer to desired direction oftravel, e.g., toward the rail car. This action can be repeated as oftenas necessary until the person reaches the rail car. At that point allthat the person has to do is to pull on the strap 32 to reengage thelocking bar. Once so engaged, the person can pull himself/herself backup on the rail car by pulling on the strap 32 as shown in FIG. 14.

It should be pointed out that while the member for pulling the lockingarm into frictional engagement with the track has been disclosed asbeing a strap, such a component is merely exemplary of various elongatedflexible members which can be used, e.g., cables, straps, filaments,etc. Thus, the use of the term strap herein is meant to cover suchalternative components. Moreover, while the use of retractors, guidesand associated components to hold the straps out of the way of theworker until necessary, is preferable, it is not mandatory. Thus,trolleys can be constructed in accordance with this invention withoutany such means for stowing the straps.

Further still, while the mechanism to releasably lock the trolley inposition has been shown and described as being manually actuable (e.g.,the straps arranged to be pulled by a suspended worker), it should beclear that any suitable automatic means can be used in lieu of themanually actuable means. Moreover, the mechanisms for releasably lockingthe trolley in position need not be limited to those assemblies thatfrictionally engage the track. In fact, the assemblies for releasablylocking the trolley in position on the track need not engage the trackat all, e.g., such assemblies may prevent rolling of the trolley on thetrack by locking one or more of the rollers via an actuatable brake,wheel chock or other device for preventing the trolley from rollingalong the track.

As should be appreciated by those skilled in the art from the foregoing,the trolleys of this invention can be original equipment or may beproduced by retrofitting existing rollable trolleys with one or moretrolley immobilizing assemblies constructed in accordance with thisinvention to releasably fix the trolley in position on a track when suchaction is desirable.

Fall Arrest Anchor Trolley:

Referring to FIGS. 15-25, a fall arrest anchor trolley 100 within a fallarrest system 500 is illustrated. The description of the fall arrestanchor trolley 100 and system below will be made with reference to FIGS.15-25.

Referring to FIGS. 15-17 concurrently, the fall arrest trolley 100 willbe described in accordance with an embodiment of the present invention.The trolley 100 generally comprises a body 120, a brake-sub system 150and a plurality of wheels 101A-D rotatably coupled to the body 120. Thebody 120 comprises a primary plate 121 having a first side surface 122and an opposing second side surface 123. In the exemplified embodiment,the first and second side surfaces 122, 123 of the primary plate 121 aresubstantially flat surfaces. However, the invention is not to be solimited in all embodiments and in certain other embodiments the firstand second side surfaces 122, 123 of the primary plate 121 can haveridges, recesses and other contours as desired. In certain embodiments,the primary plate 121 of the body 120 is formed of a rigid metallicmaterial, such as steel, iron, brass, aluminum alloys or the like. Ofcourse, the invention is not to be so limited in all embodiments andmaterials other than metal can be used in other embodiments.

In the exemplified embodiment, the primary plate 121 is generally in theshape of a trapezoid or truncated triangle with a first flange 125A at afirst end thereof and a second flange 125B at a second opposite endthereof. The primary plate 121 has various openings and/or slotsthroughout its central portion for attachment to collars of the body 120and for slidably receiving therein flanges of the brake sub-system 150as will be described in more detail below. It should be appreciated thatthe exact shape of the primary plate 121 is not to be limiting of thepresent invention in all embodiments and the primary plate 121 may takeon any other shapes that enable the trolley 100 to function as describedherein.

The body 120 comprises a first collar 126, a second collar 127 and athird collar 128. Each of the first, second and third collars 126, 127,128 can be integrally formed with the body 120, or can be formedseparately from the body 120 and connected to the body 120 at a laterstage in the manufacturing process such as by welding, adhesion,interference fit, snap fit or the like. The first collar 126 has a firstcentral opening 126A, the second collar 127 has a second central opening127A and the third collar 128 has a third central opening 128A. In theexemplified embodiment, each of the first, second and third centralopenings 126A, 127A, 128A are axially aligned along a brake axis B-B.However, the invention is not to be so limited in all embodiments and incertain other embodiments the first, second and third central openings126A, 127A, 128A may be axially offset. The body 120 is bilaterallysymmetric about the brake axis B-B in the exemplified embodiment,although the invention is not to be so limited in all embodiments of theinvention.

Moreover, in the exemplified embodiment each of the first, second andthird central openings 126A, 127A, 128A have transverse cross-sectionalareas (transverse to the brake axis B-B) that are circular orcylindrical in shape. However, the invention is not to be so limited inall embodiments and in certain other embodiments the openings 126A-128Amay take on other transverse cross-sectional shapes to correspond to theshape of the brake sub-system 150 (and more specifically to a brake rod151 of the brake sub-system) as described herein below. Furthermore, instill other embodiments the transverse cross-sectional shapes of thefirst, second and third central openings 126A, 127A, 128A may merely beable to slidably receive the brake sub-system 150 without actuallyhaving a shape that corresponds to the shape of the brake sub-system150. For example without limitation, in certain embodiments thetransverse cross-sectional shapes of the first, second and third centralopenings 126A, 127A, 128A may be rectangular while the brake sub-system150 is cylindrical. Thus, in certain other embodiments the transversecross-sectional shapes of the first, second and third openings 126A,127A, 128A are merely sized, shaped and configured to slidably receivethe brake sub-system 150 therein.

Moreover, in the exemplified embodiment, the first and second collars126, 127 are cylindrical in shape and the third collar 128 is octagonalin shape. However, it should be appreciated that the general shapes ofthe first, second and third collars 126, 127, 128 are not to be limitingof the present invention in all embodiments unless so specified in theclaims.

Referring briefly to FIGS. 15-17 and 20, the wheels 101A-D are rotatablycoupled to the body 120 by a first axle 102A and a second axle 102B. Thefirst and second axles 102A, 102B are longitudinally spaced from oneanother. In certain embodiments, the wheels 101A-D can be held in placeon their associated axles 102A, 102B by snap-rings, although theinvention is not to be so limited in all embodiments and otherstructures or mechanisms may be used to maintain the wheels 101A-D inplace on the axles 102A, 102B. In certain embodiments, the axles 102A,102B are fixedly mounted on the body 120 of the trolley 100. However,the invention is not to be so limited and in certain other embodimentsthe axles 102A, 102B may be separate components that are welded orotherwise coupled to the body 120 of the trolley 100 such as by aninterference or snap-fit arrangement.

In the exemplified embodiment, four wheels 101A-D are illustrated.However, the invention is not to be so limited and more or less thanfour wheels can be used in other embodiments of the invention. Thewheels 101A-D are rotatable about an axis E-E. Specifically, the trolley100 has two sets of wheels wherein the first set of wheels 101 a, 101Bare coupled to the body 120 and to each other by the first axle 102A andthe second set of wheels 101C, 101D are coupled to the body 120 and toeach other by the second axle 102B. In certain embodiments, the wheels101A-D are formed of a tough, wear resistant material, such aspolyamide. However, the invention is not to be so limited in allembodiments and in certain other embodiments the wheels 101A-D can beformed of any other material known to be used with trolley assemblies,such as for example without limitation plastic materials, rubber,elastomeric materials, thermoplastic elastomers, wood or metal.

Referring again to FIGS. 15-17, bottoms of the plurality of wheels101A-D collectively define a rolling plane A-A. In the exemplifiedembodiment, the rolling plane A-A is illustrated with a dotted line.However, it should be understood that the dotted line showing therolling plane A-A is a plane that is perpendicular to the page on whichthe figures are illustrated and that the rolling plane A-A iscollectively formed by all four of the plurality of wheels 101A-D. Thebody 120 comprises a first portion 130 that is located above the rollingplane A-A and a second portion 131 that is located below the rollingplane A-A. Thus, the body 120 extends through the rolling plane A-A.Furthermore, the primary plate 121 of the body 120 is orientedsubstantially perpendicular to the rolling plane A-A.

The trolley 100 comprises a first stop member 104 located at a firstlongitudinal end of the body 120 and a second stop member 105 located ata second longitudinal end of the body 120. Specifically, the first stopmember 104 is connected to the first flange 125A of the primary plate121 of the body 120 and the second stop member 105 is connected to thesecond flange 125B of the primary plate 121 of the body 120. Theplurality of wheels 101A-D are each located between the first and secondstop members 104, 105. In the exemplified embodiment, the first andsecond stop members 104, 105 are rectangular shaped plates that form theends of the body 120. Of course, the first and second stop members 104,105 can take on other shapes in certain other embodiments. The first andsecond stop members 104, 105 provide a flat surface of the trolley 100to contact an end of a rail when the trolley 100 is positioned within arail as will be described in more detail below with reference to FIG.18. Thus, the first and second stop members 104, 105 make a worker awarethat the trolley 100 has reached the end of the rail and can move nofurther in that particular longitudinal direction.

The trolley 100 also comprises one or more rollers 103A, 103B connectedto the body 120. In the exemplified embodiment, there are two rollersincluding a first roller 103A and a second roller 103B connected to thebody 120. More specifically, the first and second rollers 103A, 103B aremounted on vertically extending bolts 113A, 113B, respectively, that aresecured to the body 120 of the trolley 100. The first roller 103Aextends downwardly from a bottom of the first flange 125A of the primaryplate 121 and the second roller 103B extends downwardly from a bottom ofthe second flange 125B of the primary plate 121.

In the exemplified embodiment, the first and second rollers 103A, 103Bare cam rollers. It should be understood that the invention is not to beso limited in all embodiments and in certain other embodiments the firstand second rollers 103A-b can take on other forms, such as includingwithout limitation ball bearings, roller bearings, ball thrust bearings,roller thrust bearings, tapered roller bearings, plain bearings, flexurebearings, magnetic bearings or the like. In the exemplified embodiment,the first roller 103A is connected to the body 120 at a position betweenthe first stop member 104 and the wheels 101 a, 101B and the secondroller 103B is connected to the body 120 at a position between thesecond stop member 105 and the wheels 101C, 101D. The first and secondrollers 103A, 103B are connected to the body 120 adjacent to and belowthe rolling plane A-A. Furthermore, the first roller 103A is rotatableabout an axis of rotation C-C and the second roller 103B is rotatableabout an axis of rotation D-D. Each of the axes of rotation C-C, D-D areoriented substantially perpendicular to the rolling plane A-A.

As noted above, the trolley 100 also comprises the brake sub-system 150.The brake sub-system 150 both permits and prohibits longitudinalmovement of the trolley 100 when the trolley is positioned within a railor otherwise located such that vertical movement of the trolley 100 isprohibited as will be described in detail below. The brake sub-system150 generally comprises a brake rod 151, a brake pad 152, a lanyardconnector 153 and a resilient element 154. When the trolley 100 is fullyassembled, the brake rod 151 is slidably coupled to the body 120 so thatthe brake sub-system 150 is alterable between a free state and an arreststate, which will be described in more detail below. Thus, when thetrolley 100 is fully assembled, the brake rod 151 slides within thecentral openings 126A-128A of the collars 126-128 of the body 120.

The brake rod 151 extends along the brake axis B-B, which is orientedsubstantially perpendicular to the rolling plane A-A and substantiallyparallel to the axes of rotation C-C, D-D of the rollers 103A, 103B. Inthe exemplified embodiment, the brake rod 151 is generally cylindricalin shape. However, as described herein above, the invention is not to belimited by the shape of the brake rod 151 in all embodiments and thebrake rod 151 can take on other shapes so long as it can be slidablyreceived within the central openings 126A-128A of the first, second andthird collars 126, 127, 128 of the body 120.

The brake rod 151 comprises a sleeve 157 on its lower portion. Thesleeve 157 is essentially a larger diameter portion of the brake rod151. The sleeve 157 comprises a threaded inner surface 158 (FIG. 21) forconnecting the lanyard connector 153 to the brake rod 151 as will bedescribed below. The brake rod 151 is coupled to a first flange 155, asecond flange 156, the brake pad 152 and the lanyard connector 153.Specifically, in certain embodiments the brake rod 151 is integrallyformed with the first flange 155, the second flange 156 and the brakepad 152. However, the invention is not to be so limited in allembodiments and in certain other embodiments the brake rod 151 may beseparately formed from and later connected to the first flange 155, thesecond flange 156 and the brake pad 152 such as by welding or any otherconnection techniques described herein or known in the art. The firstflange 155 is connected to a top end of the brake rod 151 and thelanyard connector 153 is connected to a bottom end of the brake rod 151.

The brake pad 152 generally comprises a brake plate 163 having a bottomsurface 164 and a top surface 165. In the exemplified embodiment, thebrake plate 163 is a flat plate and each of the bottom and top surfaces164, 165 are flat, planar surfaces. However, the invention is not to beso limited in all embodiments and in certain other embodiments the brakeplate 163 can have a contoured or other shape. Furthermore, the brakeplate 163 is oriented substantially parallel to the rolling plane A-A.The brake plate 163 comprises at least one opening 166 therethrough. Inthe exemplified embodiment, the brake plate 163 includes four of theopenings 166. Each one of the openings 166 is a threaded hole throughwhich a set screw 167 can extend. In the exemplified embodiment, thereare four set screws 167, each of which extends through one of theopenings 166 in the assembled state. Of course, the invention is not tobe so limited in all embodiments and in certain other embodiments moreor less than four set screws 167 can be used. The set screws 167 extendthrough the openings 166 such that tip portions 168 of the set screws167 form a plurality of protrusions that extend from the bottom surface164 of the brake plate 163 of the brake pad 152. When the trolley 100 ispositioned within a rail, the tip portions 168 of the set screws 167frictionally engage upper surfaces of the rail to prevent or stop thetrolley 100 from longitudinal movement when the brake sub-system 150 isin the arrest state as will be described in more detail below.

Although the exemplified embodiment illustrates the tip portions 168 ofthe set screws 167 forming the plurality of protrusions that extend fromthe bottom surface 164 of the brake plate 163, in certain otherembodiments the set screws 167 may be omitted. In such embodiments, thebottom surface 164 of the brake plate 163 may engage upper surfaces ofthe rail when the brake sub-system 150 is in the arrest state to stoplongitudinal movement of the trolley 100. In still other embodiments,protuberances formed of rubber, metal or any other desired material maybe affixed, such as by welding, adhesion or the like, to the bottomsurface 164 of the brake plate 163 to form the component thatfrictionally engages the upper surfaces of the rail to preventlongitudinal movement of the trolley 100 when the brake sub-system 150is in the arrest state.

The lanyard connector 153 comprises a hub portion 159, an eye 160pivotably connected to the hub portion 159 by a pivot pin 161 and athreaded engagement portion 162. In the exemplified embodiment, the eye160 is a U-shaped component extending downwardly from the hub portion159. However, the invention is not to be so limited in all embodimentsand in certain other embodiments the eye 160 can take on other shapes.The eye 160 is pivotable relative to the hub portion 159 about an axisof rotation F-F that is substantially parallel to the rolling plane A-A.The eye 160 is the portion of the lanyard connector 153 to which alanyard is attached as will be described in more detail below withreference to FIG. 25. The threaded engagement portion 162 of the lanyardconnector 153 operates like a threaded screw and can be connected to thesleeve 157 of the brake sub-assembly 150. More specifically, referringbriefly to FIG. 21, the inner surface 158 of the sleeve 157 of the brakerod 151 is a threaded surface that engages the threaded engagementportion 162 of the lanyard connector 153 to couple the lanyard connector153 to the brake rod 151 of the brake sub-assembly 150.

When the trolley 100 is fully assembled and the brake sub-assembly 150is coupled to the body 120 as illustrated in FIGS. 15 and 17, the brakerod 151 extends through the first, second and third central openings126A, 127A, 128A of the first, second and third collars 126, 127, 128 ofthe body 120. Furthermore, the first flange 155 of the brakesub-assembly 150 is located above the first collar 126 of the body 120and the resilient element 154 is positioned between the first flange 155of the brake sub-assembly 150 and the first collar 126 of the body 120.Further still, the second collar 127 of the body 120 is located belowthe second flange 156 of the brake sub-assembly 150 and the secondflange 156 of the brake sub-assembly 150 is located below the firstcollar 126 of the body 120. Moreover, the third collar 128 of the body120 is located between the first and second collars 126, 127 of the body120 and between the first and second flanges 155, 156 of the brakesub-assembly 150. The brake pad 152 is located between the first collar126 and the third collar 128 of the body 120. Thus, when fullyassembled, the flanges 155, 156 and collars 126-128 are positioned froma top of the trolley 100 to a bottom of the trolley 100 as follows:first flange 155, first collar 126, brake pad 152, third collar 128,second flange 156, second collar 127.

The brake pad 152 is positioned within a first slot 170 in the primaryplate 121 that is located between the first collar 126 and the thirdcollar 128. The second flange 156 of the brake sub-system 150 ispositioned within a second slot 171 in the primary plate 121 that islocated between the second collar 127 and the third collar 128.Furthermore, the first slot 170 has a width W₁ that is larger than awidth W_(BP) of the brake pad 152 and the second slot 171 has a width W₂that is larger than a width W_(F) of the second flange 156. In certainembodiments the width W₁ of the first slot 170 is between ½ inch and ¾inch, and most preferably approximately ⅝ inch. In certain embodimentsthe width W_(BP) of the brake pad 152 is between ⅛ inch and ⅜ inch, andmore preferably approximately ¼ inch. In certain embodiments the widthW₂ of the second slot 171 is between ⅝ inch and ⅞ inch, and morepreferably approximately ¾ inch. In certain embodiments the width W_(F)of the second flange 156 is between 3/16 inch and 7/16 inch, and morepreferably approximately 5/16 inch. It should be appreciated that thewidths described above are not limited to the recited ranges in allembodiments and can have measurements outside of the recited ranges incertain other embodiments so long as W₁ is larger than W_(BP) and W₂ islarger than W_(F).

As a result of the relative widths described above, when the brakesub-assembly 150 is slidably received by the body 120, there is amplespace within the first slot 170 for upward and downward movement of thebrake pad 152 therein and ample space within the second slot 171 forupward and downward movement of the second flange 156 therein. As willbe described in more detail below with reference to FIGS. 21-24, thebrake pad 152 moves axially (along the brake axis B-B) within the firstslot 170 and the second flange 156 moves axially (along the brake axisB-B) within the second slot 171 when the brake sub-system transitionsbetween the free state and the arrest state.

In the exemplified embodiment, the resilient element 154 comprises aplurality of spring discs 169. It should be appreciated that theinvention is not to be limited to the use of spring discs 169 as theresilient element 154 in all embodiments and other components can beused as the resilient element 154 in other embodiments such as, forexample without limitation, compression springs, torsion springs,extension springs, barrel springs, spring pins, cantilever springs, leafsprings, die springs, rubber springs, wave springs, washer springs andthe like. In the exemplified embodiment, the resilient element 154comprises four spring discs 169. Of course, more or less than fourspring discs 169 can be used to create a greater or lesser spring force.

In the fully assembled state described above, the spring discs 169 ofthe resilient element 154 exert an upward force on the first flange 155of the brake sub-system 150 to bias or urge the brake sub-system 150into the free state, whereby the brake pad 152, and more specificallythe tip portions 168 of the set screws 167, are spaced a distance D₁above the rolling plane A-A. Thus, in the free state, the resilientelement 154 urges the second flange 156 axially upward within the secondslot 171 and urges the brake pad 152 axially upward within the firstslot 170. In certain embodiments, D₁ results in a clearance in a rangeof 1/16 inch to 3/16 inch, and more specifically approximately ⅛ inchbetween the brake pad 152 and the rolling plane A-A. The distance D₁ ismeasured between the tip portions 168 of the set screws 167 and therolling plane A-A (in embodiments that use the set screws 167) when thebrake sub-system 150 is in the free state. It should be appreciated thatthe distance D₁ is not limited to the above recited range in allembodiments and can be a distance outside of the recited range incertain other embodiments. Specifically, the distance D₁ is adjustableby screwing the set screws 167 further into or further out of the brakepad 152.

The spring discs 169 collectively exert a spring force K that is asufficient amount of force to maintain the distance D₁ between the tipportions 168 of the set screws 167 and the rolling plane A-A when thebrake sub-system 150 is in the free state. In certain embodiments, thespring force K is between 40 lbs. and 60 lbs., more preferably between45 lbs. and 55 lbs., and more preferably between 46 lbs. and 50 lbs. Itshould be appreciated that the spring force K is not limited to beingwithin the recited ranges in all embodiments, and the spring force K cantake on other numerical values by adding more of the spring discs 169,reducing the number of spring discs 169 or changing the tension of thespring discs 169. As noted above and as will be described in more detailbelow with reference to FIG. 25, a lanyard may be connected to thelanyard connector 153. Thus, the spring force K is greater than theweight of the lanyard that is to be attached to the lanyard connector153, and more preferably at least two to three times the weight of thelanyard attached to the lanyard connector 153, to avoid any accidentallocking or arresting of the trolley 100. Thus, the spring force K of thespring discs 169 of the resilient element 154 is sufficient to maintaina distance, such as the distance D₁, between the brake pad 152 and therolling plane A-A taking into account any components, such as a lanyard,that are normally connected to the trolley 100.

Regardless of the specific numerical value of the spring force K of thespring discs 169 of the resilient element 154, the fully assembledtrolley 100 will remain fully assembled during use of the trolley 100.Specifically, the spring discs 169 will urge the brake sub-system 150upwardly relative to the body 120 of the trolley 100. However, the brakesub-system 150 is prevented from excessive upward movement because at acertain point the top surface 165 of the brake pad 152 will contact anupper shoulder 172 of the first slot 170 of the body 120 and the secondflange 156 of the brake sub-system 150 will contact the third collar 128of the body 120. Thus, the brake pad 152 can only move between the uppershoulder 172 and a lower shoulder 173 of the first slot 170 and thesecond flange 156 can only move between the second collar 127 and thethird collar 128. Thus, all of the components of the trolley 100maintain their general relative positioning when the brake sub-system150 is slidably coupled to the body 120.

As noted above, the brake sub-system 150 is alterable between a freestate and an arrest state. In the free state, the brake pad 152 isspaced the distance D₁ above the rolling plane A-A. In the arrest state,at least a portion of the brake pad 152 is located within the rollingplane A-A. In certain embodiments, the portion of the brake pad 152 thatis located within the rolling plane A-A in the arrest state is the tipportions 168 of the set screws 167. The brake sub-system 150 is biasedin the free state by the resilient element 154 urging the first flange155 upwardly and is altered from the free state to the arrest state upona downward vertical force F₁ being applied to the lanyard connector 153while vertical movement of the trolley 100 is prohibited. Of course, itshould be appreciated that the downward vertical force F₁ required totransition the brake sub-system 150 from the free state to the arreststate is greater than any force exerted on the brake sub-system 150 by alanyard attached to the lanyard connector 153. Transitioning of thebrake sub-system 150 from the free state to the arrest state will bediscussed in more detail below with particular reference to FIGS. 21-25.

Referring to FIGS. 18-25, a fall arrest system 500 that comprises theanchor trolley 100 will be described. The fall arrest system 500comprises the trolley 100 described above and a rail 200. Commoncomponents of the trolley 100 that have been described above withreference to FIGS. 15-17 are provided with the same reference numeralsin FIGS. 18-25 to indicate relative positioning of the components, butare not described in detail with particular reference to FIGS. 18-25 toavoid redundancy in the description. It should be understood that thedescription of construction, arrangement and operation of the componentsof the trolley 100 from FIGS. 15-17 is equally applicable to FIGS. 18-25even when such description is not repeated.

Referring first to FIGS. 18-20, in the exemplified embodiment the rail200 is a rigid structure that extends along a longitudinal axis G-G. Therail 200 may be formed of any strong material, such as stainless orcarbon steel or other metallic materials. The rail 200 is formed of amaterial with sufficient strength to support the weight of a worker. Therail 200 comprises a floor 201, a pair of angularly oriented sidewalls210, 211 extending upwardly from the floor 201, a pair of verticalsidewalls 212, 213 extending upwardly from the pair of angularlyoriented sidewalls 210, 211 and a roof 214 positioned opposite the floor201 and extending between the pair of vertical sidewalls 212, 213.

The rail 200 further comprises a longitudinal slot 202 that separatesthe floor 201 into a first longitudinal section 203 and a secondlongitudinal section 204. The roof 214, opposing vertical and angularlyoriented sidewalls 210-213 and the first and second longitudinalsections 203, 204 of the floor 201 define a cavity 205. When the trolley100 is positioned within the rail 200, the wheels 101A-D of the trolley100 are located within the cavity 205, and specifically in contact withthe first and second longitudinal sections 203, 204 of the floor 201.

It should be understood that the rail 200 having the enclosedconfiguration illustrated in the exemplified embodiment is not limitingof the invention in all embodiments. Thus, in certain other embodimentsthe first and second longitudinal sections 203, 204 of the floor 201 canbe formed by separate I-beams or L-beams that collectively define thefloor 201. Thus, each of the I- or L-beams may contain one of the wheelsof each pair of wheels. Moreover, in still other embodiments the rail200 may merely omit the roof 214 or sidewalls 210-213 so that the rail200 is not enclosed. Thus, the invention is not to be limited by theparticular structural illustration of the rail provided herein in allembodiments and the rail may take on other shapes, structures orconfigurations in certain other embodiments.

The first and second longitudinal sections 203, 204 of the floor 201comprise an upper surface 206 upon which the bottoms of the plurality ofwheels 101A-D are in rolling contact. Thus, the upper surface 206 of thefirst and second longitudinal sections 203, 204 of the floor 201 of therail 200 lies substantially along the rolling plane A-A formed by thebottoms of the wheels 101A-D. In the exemplified embodiment, the uppersurface 206 of the first and second longitudinal sections 203, 204 ofthe floor 201 is a substantially flat surface. However, the invention isnot to be so limited in all embodiments and the upper surface 206 of thefirst and second longitudinal sections 203, 204 of the floor 201 can beoriented at any of various angles with the wheels 101A-D similarlyangled for smooth rolling contact therewith.

When the trolley 100 is positioned within the rail 200, the firstportion 130 of the body 120 of the trolley 100 is positioned above thefirst and second longitudinal sections 203, 204 of the floor 201 andwithin the cavity 205 and the second portion 131 of the body 120 of thetrolley 100 is located below the first and second longitudinal sections203, 204 of the floor 201. Furthermore, the body 120 and the brake rod151 extend through the longitudinal slot 202 in the floor 201 and therollers 103A, 103B are located within the longitudinal slot 202. Thebrake pad 152 and first flange 155 of the brake sub-system 150 arepositioned above the first and second longitudinal sections 203, 204while the second flange 156 of the brake sub-system 150 and the secondand third collars 127, 128 of the body 120 are positioned below thefirst and second longitudinal sections 203, 204. The lanyard connector153 is connected to a bottom end of the brake rod 151 and is alsopositioned below the first and second longitudinal sections 203, 204.

The rollers 103A, 103B have a diameter that is slightly smaller than thewidth of the longitudinal slot 202 so that the rollers 103A, 103B can becentered within the longitudinal slot 202 without contacting edges 207of the longitudinal slot 202 during normal movement of the trolley 100along the rail 200. Thus, the rollers 103A, 103B maintain alignment ofthe trolley 100 on the rail 200 and roll against the edges 207 of thelongitudinal slot 202 as necessary to maintain said alignment.Furthermore, the rollers 103A, 103B ensure that portions of the body 120that extend through the longitudinal slot 202 do not engage or bind onthe edges 207 of the longitudinal slot 202 when the trolley 100 movesalong the rail 200.

Referring now to FIGS. 18, 21 and 22 concurrently, the fall arrestsystem 500 will be described with the trolley 100 positioned within therail 200 in the free state. When the trolley 100 is positioned in therail 200 such that the wheels 101A-D are in rolling engagement with theupper surfaces 206 of the first and second longitudinal sections 203,204 of the floor 201 and there is no downward vertical force F₁ beingapplied to the lanyard connector 153, the resilient element 154 biasesthe brake sub-system 150 into the free state such that the brake pad 152is spaced above the upper surfaces 206 of the first and secondlongitudinal sections 203, 204 of the rail 200. More specifically, inthe free state the tip portions 168 of the set screws 167 that protrudefrom the bottom surface 164 of the brake pad 152 are spaced a distanceD₂ from the upper surface 206 of the first and second longitudinalsections 203, 204 of the floor 201. This relative positioning of thecomponents of the brake sub-system 150 relative to the rail 200 enablesrolling movement of the trolley 100 along the rail 200. Because theupper surface 206 of the first and second longitudinal sections 203, 204of the floor 201 is positioned along the same plane as the rolling planeA-A described herein above, the distance D₂ is substantially similar tothe distance D₁.

When the trolley 100 is positioned within the rail 200 such that thebrake sub-system 150 is in the free state, the resilient element 154 isbiased so that a gap G₁ exists between the first flange 155 of the brakesub-system 150 and the first collar 126 of the body 120 of the trolley100. As will be discussed below, the size of the gap between the firstflange 155 of the brake sub-system 150 and the first collar 126 of thebody 120 of the trolley 100 is greater when the brake sub-system 150 isin the free state than when the brake sub-system 150 is in the arreststate.

As described above, the brake sub-system 150 is received within the body120 of the trolley 100 such that the brake sub-system 150 is able toslide upwardly and downwardly along the direction of the brake axis B-B.In order to facilitate such sliding movement, a first annular gap 181exists between the brake sub-system 150 and the first collar 126, asecond annular gap 182 exists between the brake sub-system 150 and thesecond collar 127, and a third annular gap 183 exists between the brakesub-system 150 and the third collar 128. The first, second and thirdannular gaps 181-183 create an annular space between the brakesub-system 150 and the components that are integrally formed with orwelded to the body 120 of the trolley 100 to facilitate the transitionof the brake sub-system 150 from the free state to the arrest state.

Referring now to FIGS. 23 and 24 concurrently, the fall arrest system500 will be described with the trolley 100 positioned within the rail200 in the arrest state. FIGS. 23 and 24 illustrate the trolley 100, andmore particularly the brake sub-system 150 of the trolley 100, when adownward vertical force F₁ is being applied to the lanyard connector153. As described above, the downward vertical force F₁ is a force thathas sufficient strength to overcome the bias of the resilient element154. In certain embodiments, the downward vertical force F₁ is achievedwhen the trolley 100, and more specifically the brake sub-system 150 ofthe trolley 100, supports the weight of a worker who has fallen from awork surface.

When the downward vertical force F₁ is applied to the brake sub-system150 indirectly via the lanyard connector 153, a gap G₂ exists betweenthe first flange 155 of the brake sub-system 150 and the first collar126 of the body 120 of the trolley. The gap G₂ is substantially equal tothe width of the resilient element 154 (i.e., the combined width of thespring discs 169 in embodiments that use the plurality of spring discs169 as the resilient element 154). The gap G₂ is smaller than the gap G₁because when a downward vertical force F₁ is applied to the lanyardconnector 153, the entire brake sub-system 150, including the brake rod151, the brake pad 152, the first flange 155 and the second flange 156,shift downwardly relative to the body 120 of the trolley 100 in theaxial direction of the brake axis B-B.

When the brake pad 152 shifts downwardly, the tip portions 168 of theset screws 167 that protrude downwardly from the bottom surface 164 ofthe brake plate 163 frictionally engage the upper surfaces 206 of thefirst and second longitudinal sections 203, 204 of the rail 200 toprohibit rolling movement of the trolley 100 along the direction of thelongitudinal axis G-G of the rail 200. It should be understood that incertain embodiments the set screws 167 form a part of the brake pad 152such that it is the brake pad 152 that frictionally engages the uppersurfaces 206 of the first and second longitudinal sections 203, 204 ofthe rail 200 to prohibit rolling movement of the trolley 100 along therail 200. Furthermore, in still other embodiments the set screws 167 maybe altogether omitted such that the bottom surface 164 of the brake pad152 or some other component protruding from the bottom surface 164 ofthe brake pad 152 frictionally engages the upper surfaces 206 of thefirst and second longitudinal sections 203, 204 of the rail 200 toprohibit rolling movement of the trolley 100 along the rail 200.

Due to the relatively small nature of the distance D₂ between the brakepad 152 (or the tip portions 168 of the set screws 168 that protrudefrom the bottom surface 164 of the brake plate 163 of the brake pad 152)and the upper surfaces 206 of the first and second longitudinal sections203, 204 of the rail 200, transitioning from the free state to thearrest state occurs essentially immediately upon the downward verticalforce F₁ acting on the lanyard connector 153. Thus, in use, when aworker falls from a work surface, the brake sub-system 150 essentiallyimmediately transitions from the free state to the arrest state toprohibit rolling longitudinal movement (along the longitudinal axis G-Gof the rail 200) of the trolley 100. As a result, a worker who fallsfrom a work surface will remain in near enough proximity to the worksurface to be able to pull him or herself back onto the work surfaceafter a fall. This quick arrest action of the brake sub-assembly 150negates the need for a third party to rescue a fallen worker and removesany likelihood that the worker will suffer orthostatic intolerance dueto hanging from the rail 200 and trolley 100 for an extended period oftime.

Turning now to FIG. 25, the fall arrest system 500 is illustrated with aworker 301 standing on a work surface 304 and connected to the lanyardconnector 153 of the trolley 100 by a lanyard 302. The worker 301 has aharness 303 secured onto his body to support his body should he fallfrom the work surface 304. The lanyard 302 is connected to (orintegrally formed with) and extends from the harness 303 to itsconnection point with the lanyard connector 153.

The lanyard 303 can be coupled to the lanyard connector 153 by anydesired method, such as by tying the lanyard 303 directly to the eye 160of the lanyard connector 153 or attaching the lanyard 303 to the lanyardconnector 153 indirectly via another component. In the exemplifiedembodiment, the lanyard 303 is connected directly to the lanyardconnector 153 and the lanyard 303 can not be extended in length, butrather remains taut, or nearly taut with a small amount of slack, whilethe worker 301 is positioned on the work surface 304. Maintaining thelanyard 303 in this manner ensures that upon a fall, the brakesub-system 150 will expeditiously transition from the free state intothe arrest state so that momentum will not carry the worker 301 adistance from the work surface 304. Rather, the fast action of the brakesub-system 150 will lock the trolley 100 in place on the rail 200 whilethe worker 301 is close enough to the work surface 304 to pull himselfback onto the work surface 304 after a fall. Of course, the invention isnot limited to the lanyard 303 being taut and non-extendable in allembodiments and in certain embodiments, the lanyard 303 is connected tothe lanyard connector 153 by a retractor such that the lanyard 303 canbe extended or shortened as needed. The retractor may be self-retractingor otherwise.

As was described above, the spring force K of the resilient element 154(not illustrated in FIG. 25) is sufficiently strong to maintain thebrake sub-system 150 of the trolley 100 in the free state even when thelanyard 302 is connected to the lanyard connector 153. Thus, the springforce K of the resilient element 154 is greater than the weight of thelanyard 302 (and the small amount of weight exerted by the brakesystem). As a result, while the worker 301 is positioned on the worksurface 304 and connected to the fall arrest trolley 100 of the fallarrest system 500 by the lanyard 302, the trolley 100 will movelongitudinally along the rail 200 in a corresponding manner with themovement of the worker 301 along the work surface 304. However,immediately upon the worker 301 falling from the work surface 304 orotherwise initiating a downward vertical force on the lanyard connector153, the brake sub-system 150 of the trolley 100 will transition fromthe free state to the arrest state as has been described in detailherein. Specifically, upon the worker 301 falling from an edge of thework surface 304, the worker's weight exerts a downward vertical forceF₁ on the lanyard connector 153. The downward vertical force F₁overcomes the spring force K of the resilient member and alters thebrake sub-system 150 into the arrest state in which the brake pad 154frictionally engages the upper surface 206 of the first and secondlongitudinal sections 203, 204 of the rail 200 to prohibit furtherrolling of the trolley 100 along the rail 200 as has been described indetail herein above.

In certain embodiments, the worker 301 need not even pull himself backonto the work surface 304 after a fall therefrom. Rather, in certainembodiments, upon the worker 301 falling from an edge of the worksurface 304, the fall arrest trolley 100 acts as an anchor point thatreturns the user back to the work surface 304 via a pendulum motion ofthe lanyard 302. Thus, the worker 301 may fall from the work surface304, and the trolley 100 immediately locks into the arrest state againstthe rail 200. As the trolley 100 locks into the arrest state, themomentum of the worker 301 will create a pendulum motion on the lanyard302, which will swing away from and then back towards the work surface304, thereby returning the worker 301 to the work surface 304.

FIGS. 26-31 illustrate alternative embodiment of a fall arrest anchortrolley 100 i. The anchor trolley 100 i is similar to anchor trolley 100described above and depicted in FIGS. 15-25 having substantially many ofthe same components. Thus, for brevity, only the structural or othercomponents of anchor trolley 100 i that are different than the anchortrolley 100 will be discussed herein below with the understanding thatthe description above with regard to FIGS. 15-25 applies to all otherstructural components identified in FIGS. 26-31. Furthermore, thecomponents of the anchor trolley 100 i have been assigned the samereference numerals as similar components from anchor trolley 100 exceptthat the suffix “i” will be added to connote that the components arepart of anchor trolley 100 i shown in FIGS. 26-31. It will be understoodthat features that are not described below are the same as its similarlynumbered feature described above.

Referring to FIGS. 26-29, anchor trolley 100 i includes a cap 300 whichis added to protect the first flange 155 i and particularly resilientspring discs 169 i from the ingress of elements, dirt, and debris thatmight adversely effect full deformation of the spring discs and properoperation of the brake system. Cap 300 defines a socket 301 configuredfor receiving first flange 155 i and spring discs 169 i therein as bestshown in FIG. 27. Cap 300 may be made of any suitable metallic ornon-metallic material.

Anchor trolley 100 i is configured to provide a more compact designwhich facilitates use in situations where available physical space maybe more restricted. First and second stop members 104, 105 areeliminated from first and second flanges 125Ai and 125Bi, respectively,as shown. In addition, the body 120 i including primary plate 121 i isgenerally more compact in design and shortened longitudinally betweenfirst and second flanges 125Ai and 125Bi. To help facilitate this,rollers 103Ai and 103Bi are moved at least partially inboard of thewheels 101Ai-Di, as best shown in FIG. 27. In one embodiment, theoutermost extremities of rollers 103Ai and 103Bi fall on approximatelythe same vertical plane defined parallel to brake axis B-B as theoutermost extremities of wheels 101Ai-Di. Anchor trolley 100 i furthereliminates second flange 156 from sleeve 157 shown in FIG. 16 of theprevious embodiment such that new sleeve 157 i no longer includes asecond flange. This further contributes to the compact design of anchortrolley 100 i and reduces weight and component costs.

Referring to FIGS. 26-27 and 30-31, a new brake plate 302 is provided inanchor trolley 100 i which advantageously increases the applied brakingforce when the brake sub-system 150 is activated to the arrest state aspreviously described herein. In one preferred embodiment, brake plate302 includes eight (8) set screws 167 i to double the braking force incontrast to the embodiment shown in FIGS. 15 and 16. To produce thisbenefit, brake plate 302 has a generally H-shaped body 304 as best shownin FIG. 31. Brake plate 302 includes a top surface 314, bottom surface316, first end 308, opposing end 310, and opposing lateral sides 312extending longitudinally between the ends. In one embodiment, lateralsides 312 may be arranged in substantially parallel relationship. Acentral aperture 306 is provided which slidably receives brake rod 151 ithrough the aperture as shown in FIG. 27.

With continuing reference to to FIGS. 26-27 and 30-31, brake plate 302includes a plurality of set screws 167 i which are threadly engagedthrough mating threaded holes in the brake plate. In one preferredembodiment, eight set screws 167 i are provided which are comprised offour pairs of screws disposed near each corner of the brake plate 302.It will be appreciated that any suitable arrangement or number of setscrews 167 i may be used. As shown in the figures, the tip portions 168i extend below brake plate 302 as best shown in FIG. 30 to frictionallyengage upper surfaces of the rail to prevent or stop the trolley 100 ifrom longitudinal movement when the brake sub-system 150 is in thearrest state similar to the arrangement of set screws 167 shown in FIGS.15-25.

In order to provide an H-shaped body 304, a cutout 320A, 320B isprovided at each end 308 and 310 respectively. The cutouts 320A, 320Bslidably receive a portion of first and second flanges 125Ai, 125Biadjacent each lateral side of first slot 170 i (see, e.g. FIGS. 26-27),thereby allowing the brake plate 302 to have a longer longitudinallength for adding extra set screws 167 i without sacrificing structuralstrength for withstanding braking forces. When the brake sub-system 150transitions from the free state to the arrest state as described herein,the lateral portions of first and second flanges 125Ai, 125Bi adjacenteach lateral side of first slot 170 i will move vertically up/downwithin each cutouts 320A, 320B.

As used throughout, ranges are used as shorthand for describing each andevery value that is within the range. Any value within the range can beselected as the terminus of the range. In addition, all references citedherein are hereby incorporated by referenced in their entireties. In theevent of a conflict in a definition in the present disclosure and thatof a cited reference, the present disclosure controls.

While the invention has been described with respect to specific examplesincluding presently preferred modes of carrying out the invention, thoseskilled in the art will appreciate that there are numerous variationsand permutations of the above described systems and techniques. It is tobe understood that other embodiments may be utilized and structural andfunctional modifications may be made without departing from the scope ofthe present invention. Thus, the spirit and scope of the inventionshould be construed broadly as set forth in the appended claims.

What is claimed is:
 1. A fall arrest system comprising: a rail extendingalong a longitudinal axis, the rail comprising a floor and alongitudinal slot separating the floor into a first longitudinal sectionand a second longitudinal section; a trolley positioned on the rail, thetrolley comprising: a body; a plurality of wheels in rollable contactwith upper surfaces of the first and second longitudinal sections; abrake sub-system comprising: a brake pad positioned above the first andsecond longitudinal sections of the rail; and a resilient elementpositioned above the first and second longitudinal sections of the rail;a pair of rollers located within the longitudinal slot for maintainingalignment of the trolley on the rail; the brake sub-system alterablebetween: (1) an arrest state in which the brake pad frictionally engagesthe upper surfaces of the first and second longitudinal sections of therail to prohibit rolling movement of the trolley along the rail; and (2)a free state in which the brake pad is spaced a distance above the uppersurfaces of the first and second longitudinal sections of the rail toallow rolling movement of the trolley along the rail; and wherein thebrake sub-system is biased into the free state by the resilient element.2. The fall arrest system of claim 1 further comprising: bottoms of theplurality of wheels collectively define a rolling plane; the brake padcomprising a planar bottom surface that is substantially parallel to therolling plane; and wherein in the arrest state, a first portion of theplanar bottom surface of the brake pad frictionally engages the uppersurface of the first longitudinal section of the rail and a secondportion of the planar bottom surface of the brake pad frictionallyengages the upper surface of the second longitudinal section of therail.
 3. The fall arrest system of claim 2 further comprising: the firstlongitudinal section of the rail having a first longitudinal edge, thesecond longitudinal section of the rail having a second longitudinaledge, and the first and second longitudinal edges defining thelongitudinal slot; and wherein in the arrest state no portion of thebrake pad contacts the first and second longitudinal edges.
 4. The fallarrest system of claim 2 wherein the brake pad comprises a brake plateoriented substantially parallel to the rolling plane.
 5. The fall arrestsystem of claim 1 further comprising: bottoms of the plurality of wheelscollectively define a rolling plane; the plurality of wheels comprisinga first pair of wheels rotatable about a first axis and a second pair ofwheels rotatable about a second axis; and a lanyard connector positionedbelow the first and second longitudinal sections of the rail, thelanyard connector comprising a hub portion and an eye, the lanyardconnector located between the first pair of wheels and the second pairof wheels, the lanyard connector intersected by a vertical plane that isperpendicular to the rolling plane and intersects the longitudinal slot.6. The fall arrest system of claim 5 further comprising: the bodyextending through the longitudinal slot of the rail so that a firstportion of the body is positioned above the first and secondlongitudinal sections of the rail and a second portion of the body islocated below the first and second longitudinal sections of the rail;the second portion of the body comprising a collar having a centralopening; and a rod coupled to a lanyard connector and extending throughthe central opening of the collar.
 7. The fall arrest system of claim 1further comprising: bottoms of the plurality of wheels collectivelydefine a rolling plane; tops of the plurality of wheels collectivelydefine an upper plane; and the resilient element located between therolling plane and the upper plane.
 8. The fall arrest system of claim 1further comprising: the trolley comprising a lanyard connectorpositioned below the first and second longitudinal sections of the rail;a lanyard coupled to the lanyard connecter, the lanyard having a weight;and wherein the resilient element has a spring force that is greaterthan the weight of the lanyard.
 9. The fall arrest system of claim 1wherein the resilient element comprises one or more springs.
 10. Thefall arrest system of claim 1 wherein the rail is positioned at a heightabove an elevated work surface.
 11. The fall arrest system of claim 10wherein the trolley is configured to roll along the rail in a directionof the longitudinal axis in a manner that corresponds with movement of aworker along the elevated work surface when the worker is connected tothe trolley.
 12. A fall arrest system comprising: a trolley comprising:a body; a plurality of wheels having bottoms that collectively define arolling plane; a brake sub-system comprising: a brake pad positionedabove the rolling plane; and a resilient element positioned above therolling plane; a pair of rollers extending below the rolling plane, eachof the pair of rollers rotatable about an axis of rotation that isoriented substantially perpendicular to the rolling plane; the brakesub-system alterable between: (1) an arrest state in which a bottomsurface of the brake pad is at or below the rolling plane; and (2) afree state in which the bottom surface of the brake pad is spaced adistance above the rolling plane; and the resilient element biasing thebrake sub-system into the free state.
 13. The fall arrest system ofclaim 12 further comprising: the bottom surface of the brake pad being aplanar bottom surface that is substantially parallel to the rollingplane; and wherein in the arrest state, a first portion of the planarbottom surface of the brake pad is at or below the rolling plane and asecond portion of the planar bottom surface of the brake pad is at orbelow the rolling plane.
 14. The fall arrest system of claim 12 furthercomprising: the plurality of wheels comprising a first pair of wheelsrotatable about a first axis and a second pair of wheels rotatable abouta second axis; and a lanyard connector located between the first pair ofwheels and the second pair of wheels, the lanyard connector intersectedby a vertical plane that is perpendicular to the rolling plane.
 15. Afall arrest system comprising: a rail extending along a longitudinalaxis, the rail comprising a floor and a longitudinal slot separating thefloor into a first longitudinal section and a second longitudinalsection; a trolley positioned on the rail, the trolley comprising: abody; a plurality of wheels in rollable contact with upper surfaces ofthe first and second longitudinal sections; a brake sub-systemcomprising: a brake pad positioned above the first and secondlongitudinal sections of the rail; and a resilient element positionedabove the first and second longitudinal sections of the rail; the brakesub-system alterable between: (1) an arrest state in which the brake padfrictionally engages the upper surfaces of the first and secondlongitudinal sections of the rail to prohibit rolling movement of thetrolley along the rail; and (2) a free state in which the brake pad isspaced a distance above the upper surfaces of the first and secondlongitudinal sections of the rail to allow rolling movement of thetrolley along the rail; and the resilient element biasing the brakesub-system into the free state.
 16. The fall arrest system of claim 15further comprising: bottoms of the plurality of wheels collectivelydefine a rolling plane; and the upper surface of the first and secondlongitudinal sections being substantially parallel to the rolling plane.17. The fall arrest system of claim 15 wherein the rail is positioned ata height above an elevated work surface, and wherein the trolley isconfigured to roll along the rail in a direction of the longitudinalaxis in a manner that corresponds with movement of a worker along theelevated work surface when the worker is connected to the trolley.